Children as young as eight were abused at a school linked to paedophile Lib Dem MP Cyril Smith, the Mirror can reveal today.

Whistleblower Martin Digan, ex-head of care at the residential school at the centre of the revelations, told the Mirror it was a “sweet shop” for abusers.

Secret files have been found that detail appalling depravity at the Knowl View unit for disturbed youngsters in Rochdale, where Smith was a governor. Police have identified 11 other suspects.

Mr Digan said: “It is about time his sordid past was fully exposed, together with the shocking events that happened at Knowl View. I’m glad it is out but I’m sickened it has taken so long.”

The shocking details have come to light as the Liberal Democrats are threatened with legal action by Smith’s victims.

They will seek damages if it can be proved senior party officials knew of his crimes – but failed to stop him.

And ex-children’s minister Tim Loughton has called for former Rochdale MP Smith, who died in 2010, to be stripped of his knighthood.

It follows revelations about Smith’s behaviour in a book by the town’s Labour MP, Simon Danczuk.

He claims Special Branch and Lancashire police halted two inquiries into Smith, evidence against him was ignored and no action was taken when child porn was found in his car.

The book also claimed the leader of Rochdale’s Liberal Party, Henry Howarth, tried to bully police into dropping inquiries into the 29-stone monster.

It adds director of public prosecutions Sir Norman Skelhorn refused to prosecute Smith in 1970.

Richard Scorer, a solicitor representing six men who claim to have been molested as boys by Smith, said: “We are examining who knew what about the MP and that includes the Liberal Democrat party and Rochdale Council.”

However, Lib Dem leader Nick Clegg insisted yesterday his party knew nothing about the “­repugnant” sex attacks.

Vince Cable last night told ITV’s The Agenda: “It is really horrific.”