Allegations of corruption and doping cover-ups at the International Weightlifting Federation are "very serious and worrying", the International Olympic Committee has said.

A documentary made by German state broadcaster ARD alleges that millions of dollars paid by the IOC to the IWF is unaccounted for and features a team doctor from Moldova claiming that clean drug tests can be "bought".

A statement from the IOC read: "The IOC takes note of the ARD report. The accusations are very serious and worrying.

"The IOC wants to clarify that - contrary to what ARD is claiming - it was not in possession of 'most of the documents' on which the film is based.

"This applies to the documents regarding the doping statistics and those regarding the alleged financial irregularities."

The documentary features a Thai competitor, Rattikan Gulnoi, confessing to doping during the London 2012 Olympics.

In relation to this, the IOC said a disciplinary commission chaired by executive board member Denis Oswald had been set up to "follow up" on the confession.

The IWF said in a statement released on Monday: "On 5 January, German TV channel ARD broadcast a show in which a former Thai weightlifter, Rattikan Gulnoi appeared to have implicated herself and other Thai weightlifters in doping.

"The IWF has immediately followed up with the Thai federation. The IWF has also requested copies of ARD's materials.

"The widespread abuse of the same anabolic agent, especially among juniors, in Thailand would appear to be indicative of an organised system of doping that may have extending beyond the sanctioned athletes themselves.

"This impression would appear to have been reinforced by the apparent confession secured by ARD. The IWF will now confer with WADA in order to establish whether a wider investigation may be appropriate."