A senior German MP has said that he has been told of "many distasteful things" on board a naval training ship at the centre of mutiny allegations.
Parliamentary commissioner Hellmut Koenigshaus was speaking amid increasingly lurid accounts of sexual harassment and bullying.
It emerged last week that cadets on board the Gorch Fock refused orders to climb the rigging after a trainee died.
The German government has appointed a commission to investigate the affair.
The media have dubbed the ship "Germany's biggest floating brothel" after reports of crew being regularly drunk on board and a male cadet being approached in the showers by several trainers and ordered to pick up a shampoo bottle.
The scandal has put pressure on Defence Minister Karl-Theodor zu Guttenberg, whose opponents say it is proof that he has no control of his ministry.
Mr zu Guttenberg's response to the reported mutiny was criticised when he said initially that people should not make hasty conclusions, and then hours later announced that the ship's captain Norbert Schatz was being suspended.
His critics argued he was looking for a scapegoat.
The defence minister has also come under pressure over the death of a German soldier in Afghanistan. Initially it was reported that he had shot himself by mistake but it has since emerged that he was killed accidentally by a fellow soldier.
Mr Koenigshaus has visited the ship and has called for a thorough investigation.
"There are some things that are just not right - that has to be said quite plainly," he told ZDF television.
A commission has now been appointed to investigate the matter further, and it plans to go to the training ship, which is still in South America, to interview people involved.
The defence minister is expected to testify before a parliamentary committee on Wednesday.