AN investigation is under way after the head of Edinburgh's transport department made an allegation of bullying against another senior council officer.

The case raised by head of transport Marshall Poulton against Mark Turley, director of services for communities, is rare because it involves one director raising a complaint about another.

The roles of senior officers overlap in a number of aspects of their work, although as a director Mr Turley, whose salary is £123,525, is more senior. The council has declined to disclose Mr Poulton's salary.

Details of the allegation are unclear at this stage but they are understood to relate to claims of bullying.

Mr Turley is involved in overseeing the revamp of the council's Property Conservation Department, which is responsible for home and business repairs, following a police fraud investigation.

No criminality was discovered by the probe, but fraud squad officers reported that workers accepted gifts including alcohol and a night out to a strip club from contractors.

Mr Poulton does not have specific duties related to the behind-schedule trams project – the budget for which has risen from £545m to £776m – but his role includes transport policy and planning, strategic traffic control, road safety, parking operations, roads design, operation and maintenance and cycling initiatives.

An officer from another department, of equal rank to Mr Turley, is handling the complaint. Standard practice while a complaint is being investigated would be to "manage" contact between officers.

Mr Poulton took over as head of transport at the council in 2008. He was previously the engineer responsible for highway planning, traffic management and feasibility studies at the then Strathclyde Regional Council and in 2005 was head of technology systems, with responsibility for looking after London's traffic control centre and delivery of the Olympic route network ahead of the 2012 Games.

Mr Turley is a former rent collector who then qualified as a Member of the Chartered Institute of Housing and studied business administration.

After progressing through various management positions he was appointed deputy director of housing for York City Council in 1990.

In December 1993 he began working for Edinburgh City Council as director of housing, becoming the director of services for communities in 2006.

He is described as the lead director for a wide range of initiatives aimed at improving the quality of the council's performance and has served on a number of national bodies including the Homelessness Task Force.

A source said the officers possibly had the two most difficult jobs in Scottish local government.

A council spokesman said: "We don't comment on the details of individual cases but we can say that the council has strong processes in place for dealing with concerns or complaints, and these will be followed appropriately."

Mr Poulton and Mr Turley both declined to comment.