A Holyrood investigation has found no evidence that SNP MSPs inappropriately used parliamentary postage.

Ten MSPs and their staff were interviewed after an anonymous complaint suggested stamps bought with Scottish Parliament expenses were passed to general election candidates for campaigning activities.

The Scottish Parliament Corporate Body (SPCB) said the MSPs provided reassurances that they and their teams had not given stamps to others for election purposes and confirmed no further action would be taken.

It said there would be a future review of the way that parliamentary postage is run.

The SPCB is a cross-party body of MSPs chaired by Presiding Officer Alison Johnstone, who received the complaint.

In an email seen by the BBC last month, an individual claimed stamps bought on expenses were given to Westminster candidates to help with campaigning, such as sending letters to voters.

BBC Scotland News also viewed a screenshot from a WhatsApp group, made up of staff who work for SNP MSPs, that included a discussion about whether or not the stamps can be traced back to the purchaser.

The SPCB said: “Following a thorough investigation, officials have found no evidence that stamps were used inappropriately. Therefore, no further action is required.

“Ahead of the next session the SPCB will carry out a review of stamp purchasing, as part of its sessional review of the members’ expenses scheme, to ensure the current approach is the most suitable.”

MSPs are allowed to spend up to £5,500 a year on postage and stationery as part of parliamentary resources.

The Scottish Parliament’s rules state that they “must be used only for parliamentary duties and must not be used for any other purpose, including party political purposes”.

There are legal limits on how much political parties and candidates are allowed to spend during campaigns.

First Minister John Swinney said last month he was confident no public money had been used on the SNP’s election campaign.

In the WhatsApp correspondence examined by the SPCB, one SNP staffer said the “stamp fairy” was good for campaigns.

When questioned what they meant, the person said they were referring to local campaigns run by MSPs in their constituencies and not election campaigns.

Election agents in the MSPs’ constituencies were also contacted to see if they had received stamps from the Scottish Parliament to use in the campaign.

All said they had not.

A spokesperson for the SNP Holyrood group welcomed the findings.

They added: “It is extremely disappointing that obviously light-hearted comments were deliberately taken out of context in an attempt to smear individuals and cause damage during an election campaign.”