The president also said he would co-operate "in any investigation" in Australia and "will also instruct the relevant local authorities to investigate".

Theage.com.au has reported that Snowy Mountains Engineering Company’s (SMEC) overseas staff allegedly bribed officials to secure a $2.3 million aid-funded sewerage project in Sri Lanka in 2011 and, in partnership with a Canadian company, a $2.2 million power plant project in Bangladesh in 2007.

Company emails also reveal Sri Lankan President Maithripala Sirisena and his adviser allegedly demanded a political "donation" to be paid by SMEC when Mr Sirisena was a cabinet minister.

The emails show a plot to skim the money off a World Bank-funded dam project in 2009. In return, Mr Sirisena was to approve the awarding of the dam contract to SMEC, worth $1.82 million.

SMEC's Sri Lankan manager, who was recently sacked, wrote in emails to two Australian colleagues that he wanted to "inform the minister/co-ordinating secretary" of the size of an alleged kickback to be paid and that he needed to "prioritise" certain payments to unnamed parties "since the signing of the contract would depend" on it.

SMEC has confirmed a "request for a political donation", but insists an internal investigation found no donation was made and the firm "continues to fully co-operate with the AFP (Australian Federal Police)."