The Office of the Scottish Charity Regulator was asked to probe a £512,000 severance 'golden goodbye' for Ronnie Saez of Glasgow East Regeneration Agency from the city council.
In January John Mason, Shettleston SNP MSP asked for an investigation into the payment. In April he asked for an update on proceedings and the OSCR stated their inquiries were continuing and Mr Mason would be informed once they had been concluded.
Mr Mason has asked for details of the case but is concerned that he has been given no information and has asked the Scottish Government to seek clarification about the investigation.
Mr Saez was awarded a severance payment of £42,000 and a pension con- tribution worth £470,000, when he left his post in March 2011 aged 50.
The deal was approved by the GERA board of five directors, including three city Labour councillors, Jim Coleman, George Redmond and Catherine McMaster.
After leaving GERA, Mr Saez became a director of Divercity and Regeneration Solutions UK, which is based at his home in Paisley.
Mr Mason said: "I am becoming increasingly concerned about OSCR's reluctance to disclose what information they may have on the payoff of Mr Saez.
"They have had more than eight months to investigate the matter.
"This exceeds their target quoted in their Inquiry and Intervention policy, which states: 'We aim to conclude inquiries within as short a period as possible, generally within 6 months'.
"Mr Saez's morally questionable pay off of more than £500,000, sanctioned by Labour councillors, needs explained and the public needs to have confidence that the regulator is able to deliver what it is designed for.
He has contacted Fergus Ewing, Scottish Government minister with responsibility for charities, stating his belief the pay out is "morally questionable" and asking him to intervene.
The OSCR said its target is 74% of cases within nine months but some can take longer.
A spokesman for OSCR said: "We consider each case on individual circumstances."