A mix-up over the interpretation of this year's Scottish exam results appears to have been resolved, amid concerns that 1,000 youngsters face an anxious wait to find out if they have gained university places.

A major investigation has been launched into how the Universities and Colleges Admissions Service (Ucas) managed to give a number of pupils more marks than they deserved.

Ucas said on Tuesday evening that it had corrected its database and would send the updated records to UK universities immediately.

It apologised to candidates for the error, but maintained their academic prospects would not be damaged as a result.

Earlier, the Scottish Qualifications Authority (SQA), which issues exam certificates, said it understood Ucas had incorrectly interpreted Scottish data.

We do not expect any applicant to be disadvantaged

Tony Higgins Ucas chief executive

The problems emerged as thousands of Scottish students received their results on Tuesday morning.

Ucas confirmed it believed the data it had received from the SQA was accurate.

A statement from the SQA said: "We are talking with Ucas and are doing everything we can to assist them through this difficulty."

The problem stemmed from the fact that Scots students were given a "fall back" mark if they obtained 48% or 49% in exams, rather than being given a fail.

Separate investigation

Ucas staff have incorrectly classified this as a C (pass) mark and given pupils additional points in their applications for universities across the UK, an SQA spokesman said.

Ucas chief executive, Tony Higgins, said: "The only applicants who may have been affected by this problem are those who have a C6 for either a Higher or Advanced Higher result.

"Ucas would like to apologise to them. We will be writing to them tomorrow morning (Wednesday) at the latest to explain what will happen next.

"We do not expect any applicant to be disadvantaged."

The mix-up comes just two years after the SQA came under fire when thousands of students received incorrect or late exam results.

A spokeswoman for the body said an investigation had been launched to find out exactly what had happened and how it had occurred.

Scottish education minister Cathy Jamieson said she was disappointed by the mix-up but was quick to point out that neither the Scottish Executive nor the SQA were to blame.

She said: "The SQA passed on correct information to Ucas.

Cathy Jamieson confirmed there was a problem

"It appears Ucas has misinterpreted some of the data and has given erroneous information to some universities. It has been asked to rectify this very quickly."

The Scottish National Party's education spokesman Michael Russell criticised the mix-up.

"It is unforgivable for a body handling such sensitive and important information to make a mistake which will create great insecurity and worry for so many of Scotland's young people," he said.

Mr Russell added: "Ucas is playing fast and loose with the future of a whole generation of Scotland's senior school pupils and it must get its act together fast."

It follows news that a separate investigation has been launched to find out why there was a 2.2 percentage point fall this year in the number of candidates passing Higher exams - the equivalent of A-levels in England, Wales and Northern Ireland.