The bailout of Prestwick airport could reach almost £40 million by 2018, Scottish government figures reveal.

A previous projection by Audit Scotland suggested it would not reach this level until 2021-22.

Repayments on the loans are not scheduled to begin until the airport starts making a profit, which could be 2023 according to last year’s Audit Scotland report.

It said the government planned to sell Glasgow Prestwick airport back to the private sector once the airport was viable.

The airport was bought for £1 from previous owners Infratil three years ago

Audit Scotland had warned in February 2015 that loans could reach up to £39.6 million by 2021-22.

However, government figures suggest £39.5 million could have been given in loans by the end of the 2017-18 financial year, the BBC reported.

The airport is being earmarked as possibly becoming the UK’s first space port launch site and to also benefit from a new Heathrow runway by becoming a logistics hub.

A Scottish government spokesman said its investment in the airport was on a commercial basis, in the form of loan funding.

“This attracts a market rate of interest in line with state aid rules.

“A report from Audit Scotland confirmed that we are highly likely to generate a return on our investment that is higher than the current rate of interest we are charging the airport.”

The Scottish government has not set a limit on overall loan funding for the airport.