One of the five Siptu national trustees investigating who in the union went on foreign study trips funded by a HSE-backed €60m SKILL training programme, is not involved in the probe as he himself went on three of the controversial trips.

While Siptu has refused to comment until the investigation is complete, it is understood that one of the trustees, Brian Bird, is not involved in the probe.

Bird is employed by Cork City Council and is also one of five elected Siptu trustees who oversee the union's financial affairs.

According to a HSE internal investigation into the whereabouts of €2.35m handed over to an account bearing the Siptu name to help run the staff training programme, Bird went on three week-long study trips to the US – New York in 2006, Boston in 2007 and Savannah, Georgia in 2008.

While these were designated study trips for those union and government officials running the SKILL programme, all three trips coincided with St Patrick's Day.

The HSE said that €2.35m was given over five years to an account called the 'Siptu national Health and Local Authority fund'.

The money was supposed to support research, expenses etc, of those union and government officials involved in running the €60m SKILL training programme.

But the HSE claims it has no records of how the money was spent and who and why they went on over 30 such foreign 'study trips' to the US, Australia, Hong Kong and the UK.

Siptu said the account into which the money was paid was not an authorised union account and it had no knowledge of its existence until so advised by the HSE.

It has emerged since that the account was operated by a senior official of the union, Matt Merrigan, who heads up the union's health division with another union lay official. Merrigan is currently on sick leave.

The union also said it had frozen the controversial account and had promised to pay back any monies to the HSE if that proves to be the case.

Meanwhile, in a row within a row, the Department of Finance has called into question the HSE's list of people who went on these trips.

According to the HSE, whose investigation is based on interviews with its staff who went on the trips, a senior official in the Department of Finance, Tom Dowling, went on two trips to New York in January 2005 and March 2006.

But in what could prove to be embarrassing for either the HSE or the department, a note appended to the HSE's list said the department had identified that Dowling "was not on this trip as he was keyed in on the Department of Finance attendance system during this period".