Ozil meets Erdogan and other controversial sporting photo ops

Arsenal midfielder Mesut Özil was criticised after meeting the Turkish president in May

Posing for the camera is an everyday occurrence for most sports stars, but there are times when a photo opportunity can quickly lead to criticism and controversy.

Take German footballer Mesut Ozil, who quit the international team following a backlash over his photograph with Turkish President Recep Tayyip Erdogan.

Ozil is of Turkish origin, and met the country's leader in May to "respect the highest office of my family's country".

But the image led some to question his loyalty to German democratic values.

Mr Erdogan's party has cracked down on opponents and he has purged the military, police and judiciary.

• Turkey's pugnacious president

• Erdogan's Turkey - the full story

• German furore over Erdogan photos

Ozil's critics included the German Football Federation (DFB) which said "football and the DFB defend values which are not sufficiently respected by Mr Erdogan".

The controversy raised questions about the significance of sportspeople meeting politicians, and whether a smiling photograph can be considered an endorsement.

But it is by no means the first incident of this kind.

Mohamed Salah and Ramzan Kadyrov

Chechen leader Ramzan Kadyrov shakes hands with Egyptian footballer Mohamed Salah

At first glance it appears to be an ordinary handshake, but this image led to accusations that Egypt and Liverpool player Mohamed Salah was being used for political propaganda.

He was photographed meeting the controversial leader of Chechnya, Ramzan Kadyrov, who has been accused of a string of human rights abuses.

The pair met last month in the Chechen capital Grozny, where the Egyptian team had based its World Cup training camp.

• Ramzan Kadyrov: Putin's key Chechen ally

• 'They want to exterminate us', says Chechen gay man

• Chechen 'gay purge' victim speaks of torture

Human rights groups criticised world football body Fifa for involving the Russian republic in the tournament and condemned the photograph.

"Ramzan Kadyrov was always going to see Mo Salah as a walking photo opportunity," Amnesty International's Allan Hogarth said at the time.

"During Kadyrov's authoritarian rule in Chechnya there have been a stream of reports of enforced disappearance, of detainees being tortured and even extrajudicial executions."

Earlier this year, the Chechen leader defended his human rights record to the BBC and insisted all reports of extrajudicial killings and torture were "made up".

Dennis Rodman and Kim Jong-un

Kim Jong-un watches a basketball game in Pyongyang with former NBA star Dennis Rodman

There are unlikely friendships, and then there is North Korean leader Kim Jong-un and ex-basketball star Dennis Rodman's friendship.

Rodman made his first trip to North Korea in 2013, when Vice Media arranged for his team the Harlem Globetrotters to have an exhibition match there.

He has since made several trips to the country and met Kim Jong-un, who is known to be a big basketball fan, on multiple occasions.

But Rodman has been criticised for his refusal to address North Korea's human rights violations.

The country has been known to conduct public executions, send people to brutal labour camps, and spy on its citizens using a vast surveillance network.

"No-one's ever seen the [human right's abuses], no one's ever seen it on TV, it's all hearsay," Rodman told NBC's Today programme earlier this year.

Conor McGregor and Vladimir Putin

Conor McGregor praised the Russian president as "one of the greatest leaders"

Conor McGregor is arguably the most high-profile mixed martial arts fighter in the world.

He is so well-known, in fact, that Russian President Vladimir Putin apparently invited him to the World Cup Final in Moscow as a special guest.

McGregor posted to his more than 24 million followers on Instagram expressing his gratitude for the meeting and appreciation for the Russian leader.

"This man is one of the greatest leaders of our time," he wrote. "Today was an honour for me Mr Putin."

But his praise for a man who is often criticised over Russia's human rights record was met with a fierce backlash.

"A great fighter, a poor judge of character," one Twitter user wrote. "Research the history," another said.

René Higuita and Rodrigo Londoño (Timochenko)

René Higuita demonstrates his trademark move during an exhibition match in 2012

Former Colombia goalkeeper René "El Loco" Higuita is best known for inventing the "scorpion kick" he used to make a save against England at Wembley in 1995.

But he found himself in hot water in 2016 after being pictured alongside the leader of the demobilised Farc rebel group.

• Who are the Farc?

More than 260,000 people were killed in more than five decades of armed conflict between the Farc and other rebels, government forces and right-wing paramilitaries.

This made the image, in which Higuita can be seen raising the arm of the then Farc leader Rodrigo Londoño, particularly sensitive.

"I have met military leaders, paramilitary leaders and guerrilla leaders, and they are all Colombians, and I have known their hearts," Higuita said at the time.

Rodrigo Londono - known as Timochenko - led the Farc guerrillas