The UK Government has rejected calls for a more flexible post-study work visa system for international students in Scotland.

Immigration minister Robert Goodwill insisted the four current visa categories available to non-European Economic Area (EEA) graduates of UK universities already "comprise an excellent post-study work offer".

A House of Commons Scottish Affairs Committee inquiry concluded in February that the removal in 2012 of a scheme that allowed overseas graduates to work for two years after completing their studies had made Scotland a less attractive destination to study.

The committee's report cited an 80% drop in non-EU students remaining in the UK after graduating and said change was necessary to address demographic challenges north of the border and fill skills gaps in areas including health and finance.

In a response published by Goodwill, the UK Government said the previous system had been subject to "widespread abuse" which had "damaged the reputation of our education system".

"This was supported by evidence that the availability of the tier 1 (post study work) category gave rise to a cohort of migrants who, to a significant degree, were unemployed or engaged in unskilled work and were likely to seek to abuse the immigration system in order to prolong their stay," it said.

The government also noted that visa applications from international students to study at Scottish universities had increased by 10% since 2010.

"Applying different immigration rules to different parts of the UK would complicate the immigration system, harming its integrity, and cause difficulties for employers with a presence in more than one part of the UK," it concluded.

The government added: "We have taken important steps to reform the student migration system and we have no plans to reintroduce a post-study work scheme that does not lead to skilled work and could reintroduce many or all of the issues we saw under the former tier 1 (post study work) category."

A pilot is taking place at the universities of Oxford, Cambridge, Bath and Imperial College London to simplify the visa application process for Masters students and grant them an additional six months leave to remain after the end of the course to find a graduate job under Tier 2 visa rules.

The government said: "The institutions taking part in the pilot were chosen due to their consistently low level of visa refusals.

"Should the pilot be a success, the Home Office will be considering expansion of the pilot further, including to highly-compliant institutions in Scotland."

In August, Scottish ministers urged the UK Government to include Scottish universities in the pilot without success.

SNP MP Pete Wishart, who chairs the Scottish Affairs Committee, said he was "extremely disappointed" by the latest response.

He said: "Despite the almost universal support for improving post-study work schemes in Scotland, we are still to see these factors have any influence on the direction of policy.

"We reiterate our call for the UK Government to engage constructively with Scottish higher education institutions on this issue.

"The government must also speak to employers about the struggles they have in recruiting for key sectors.

"They must work with their Scottish counterparts to explore formal schemes that would allow those who come here to study to stay and contribute to the economy.

"The calls from Scotland are overwhelming, it is time for the UK Government to listen."

A UK Government spokeswoman added: "The UK continues to welcome genuine students coming to our world-class universities and we are determined to make sure that what we offer brings real benefits to this country.

"As the Home Secretary announced earlier this month, we will be consulting on what more we can do to strengthen the system to support the best universities across the UK - and those that stick to the rules - to attract the best talent.

"This is not about pulling up the drawbridge to reduce student numbers, but making sure that those students that come here, come to study."