The education watchdog has launched an investigation into grade inflation after a “sharp increase” in the awarding of first and upper second-class degrees at several universities.

The Office for Students (OfS) said the rates of students with top degrees at three universities and colleges, which have not been named, raised “potential concerns that require further scrutiny”.

In the last decade, the proportion of firsts handed out in England has more than doubled, prompting fears that degrees will be seen as devalued.

If the universities or colleges are found to have broken OfS rules, they could be fined up to £500,000 or 2% of their income.

The fact that the OfS is conducting these investigations should not be interpreted as indicating that any form of wrongdoing has actually taken place

The regulator requires institutions to award qualifications that are “credible” compared with previous years, and based on “the knowledge and skills of students”.

Grade inflation, the practice of rewarding the same level of student achievement with increasingly higher degree classifications, is explicitly banned.

The OfS said in a statement: “The decision to open these investigations means that the OfS has identified potential concerns that require further scrutiny at the three providers.

“The fact that the OfS is conducting these investigations should not be interpreted as indicating that any form of wrongdoing has actually taken place.”

Although the watchdog declined to name the universities and colleges under scrutiny, it intends to publish further details “in due course”.

In the 2020-21 academic year, 37.9% of students were awarded a first-class degree, up from 15.7% in 2010-11.

Two months ago, Universities UK and GuildHE – representing 197 UK universities – pledged to return the proportion of top degrees to pre-pandemic levels.

“We cannot lose sight of the need to maintain the value of a degree and so must redouble our efforts to identify and address unexplained increases in firsts and 2:1s,” they said in a joint statement.