By Paul Hutcheon

A local authority leader and his civil partner are facing an investigation after failing to declare that their company advised a businessman on a development plan they subsequently backed.

John Stewart, the new leader of Aberdeen City Council, and fellow Liberal Democrat councillor Neil Fletcher, helped approve the city-wide "local plan" when it was pushed through last year.

However, the pair declined to mention that their firm, Cairncry Consultancy Ltd, had advised property developer Alan Massie on the plan's implications for his business.

Massie has said he will not use the firm in the future, while Fletcher said he received around £7000 in fees from the tycoon.

This newspaper last week revealed how Massie was the key client of Stewart and Fletcher's firm.

Massie's firm, Carlton Rock, has significant interests in the decisions of the council, including a £50 million land deal at Pinewood and Hazledene.

The two councillors, who entered into a civil partnership in 2005, were criticised after Fletcher said he talked to council officials about the land deal on Massie's behalf.

The revelation prompted another LibDem councillor, Martin Greig, to pass on complaints about the apparent conflict of interest to the council's solicitor.

The two councillors are facing more questions after it emerged they both backed the council's local plan in June last year.

The plan outlined areas of the city that could be used for residential development, including Pinewood and Hazledene.

Fletcher told the Sunday Herald that he advised Massie on the plan in the weeks before it was pushed through.

"I spent a lot of time with Alan going through affordable housing and how that was going to affect his developments. The local plan was due to be adopted. Alan suggested I could work with him on the affordable housing elements."

However, the minutes of the June meeting that approved the plan show that neither Fletcher nor Stewart declared their financial interest.

In a statement issued on behalf of both councillors, Fletcher said: "The legal advice was quite clear about this. The vote was not specifically about one piece of land, it was about the whole city."

Willie Young, the secretary of the Labour group on the council, has said he will make a complaint to a local government ethics watchdog. "This is a very serious matter," he said. "If the council does not report this to the Standards Commission, then I will."

Massie said hiring Cairncry had caused him "heartache" and was a bad business move that he would not repeat.

He also said he had urged the council to probe Martin Greig's voting record on issues relating to his company.