An alleged conman “invented” documents and “forged” signatures in order to swindle AIB out of £740 million, a London court has heard.

Alexander Williams and Achilleas Kallakis are accused of defrauding the bailed-out bank out of £740 million by applying for property loans with fake guarantees.

Mr Williams was questioned about guarantees alleged to have been faked in the name of Mike Wong and Walter Kwok, executives at Hong Kong estate agents Sun Hung Kai Properties.

He told jurors that the trust on whose behalf the loans had been taken out had an informal “memorandum of understanding” with SHKP, under which the Hong Kong group sanctioned the deferral of their share of the profits. However, the memorandum document was lost from the Monaco office of Mr Kallakis and Mr Williams in 2009, it was said.

Cross-examining Mr Williams at Southwark Crown Court yesterday, Annabel Darlow, prosecuting, asked: “You had a memorandum of understanding signed by Walter Kwok in a file in Monaco saying defer our profits until later on – are you making this up as you go along?”

She also said: “These documents were invented, with forged signatures intended to give the bank an impression of a business relationship with SHKP.”

Mr Williams again denied that suggestion.

Asked about denials by Mr Kwok and Mr Wong that the signatures were theirs, Mr Williams accused Mr Kwok of being a “maverick” doing deals on the side.

Ms Darlow then asked Mr Williams why he had not secured a UK-based guarantor and suggested the choice of a Hong Kong-based company was “to reduce the likelihood that the lending bank would find out that the company had no involvement in the transaction”.

Mr Williams said they did not have UK connections to go for a local guarantor.

He also denied forging a reference for Mr Kallakis from Lord Harris of High Cross, which described him as “achieving what it took some of the greatest people in history a lifetime to achieve”.

The trial continues.