A newly-elected Labour MSP was disciplined in a previous post after verbally abusing and intimidating a colleague from an ethnic minority, the Sunday Herald can reveal.

Anne McTaggart was moved to another job and attended an anti-racism course after her employer upheld a raft of complaints against her.

A spokesman for Scottish Labour said the party would be asking “a number of questions” about the revelations.

McTaggart, 41, was elected as a Glasgow List MSP at last month’s Holyrood election. An ally of Steven Purcell, the disgraced former city council leader, she is also a councillor for the Drumchapel and Anniesland ward.

Before being elected as a local representative in 2009, she was employed by Glasgow City Council.

However, McTaggart’s employment as a community support worker was marred by controversy.

An investigation has revealed two colleagues made a total of four separate complaints against her in 2006. Three of the four, this newspaper has learned, were upheld.

One complaint centred on claims McTaggart made a threatening remark about a co-worker. Another complaint focused on accusations she intimidated another colleague.

The final investigation related to allegations McTaggart referred to the same employee, who is from an ethnic minority, in disparaging terms.

Following a disciplinary hearing, McTaggart received a warning and was relocated to another part of the city. She was also suspended for a short period and attended equalities training.

A source close to the MSP said the course was also attended by other colleagues.

The source added McTaggart denied that the inappropriate language included describing her former council colleague as “the bomber”.

It is understood potential Labour candidates have to inform party officials of any ‘skeletons in their cupboard’ before they are approved.

A Labour insider said: “We didn’t know anything about these complaints. Anne did not make us aware of them. She would have been asked if there were any issues like this, but she did not say anything.”

Within three years of the complaints being upheld, McTaggart was elected to the council after a by-election.

Labour sources have linked her council candidacy to the political influence exercised by Purcell.

He quit as council leader last year after admitting taking drugs.

Although McTaggart was a candidate on the List ballot, nobody in Labour expected her to get elected to the Scottish Parliament. It was only Labour’s loss of first-past-the-post seats to the SNP that secured her presence at Holyrood.

Following McTaggart’s election, the Sunday Herald reported how Labour group leader Iain Gray warned her against hiring Purcell as a staff member. Labour sources feared Purcell may have used a job with his political ally as a first step towards a comeback.

James Dornan, the SNP MSP for Glasgow Cathcart, said: “If these allegations are correct, then it is a damning indictment on Labour in Glasgow. Serious questions have to be asked about when they first learned about these complaints regarding Anne McTaggart.”

A Scottish Labour Party spokesman said: ”We expect and demand the highest standards from our candidates so we will be asking a number of questions about this.”

A council spokesman said: “We never comment on personal matters.”