The Scottish government has been urged by a shadow minister to investigate Citizens Advice Scotland, following the resignation of its finance director on Monday and suspension of its chief executive last year.

Alex Johnstone, Conservative shadow minister for communities and housing in Scotland, said the resignation of the charity’s finance director Jon Dye was a “deeply worrying development” for the charity.

“I am concerned about the finances of a charity that has received large funds from the UK and Scottish governments. It is time someone stepped in here to provide reassurance,” he told Civil Society News.

“If the government does not know why the chief executive was suspended, or why the head of finance has quit, they should be investigating to ensure accountability.”

Dye’s “sudden” resignation on Monday came as a surprise to staff at Citizens Advice Scotland, according to Scottish newspaper the Herald Scotland.

According to the paper, colleagues learned of his resignation in an email from the acting head of human resources and from a document that thanked other members of the finance team individually for their “hard work and dedication over recent months”.

CAS is an umbrella body for 61 member offices that advise 300,000 people a year on finance, welfare and consumer issues.

Much of the charity’s £13.4m income comes from the Scottish and UK governments – including £2.7m from the Scottish government, £4m from the Department of Business Innovation and Skills and £1.1m from HM Treasury.

Dye’s resignation follows the suspension of chief executive Margaret Lynch last September. No explanation has been given for her suspension but according to minutes of a trustee meeting revealed to the Herald Scotland, trustees raised concerns about financial management and low reserves at the charity.

A spokesmen for CAS confirmed to Civil Society News that Lynch was still suspended but said the charity did not “comment on staff changes”.

But he added: “In terms of the vacancy of head of finance, we are looking to recruit a replacement as a priority.”