Child abuse probe 'scrapped' after Smith arrest

The BBC has heard claims that an investigation which allegedly uncovered child abuse by the late Liberal MP, Cyril Smith, was scrapped just after he was arrested in 1981.

It is understood police officers released him after a few hours and were then ordered to give up all their evidence.

Now, MPs Tom Watson and Simon Danczuk have called for David Cameron to protect any officers giving evidence to an inquiry against prosecution under the Official Secrets Act.

Tom Symonds reports.