A lack of consistency in the way UK universities punish cases of plagiarism has been revealed by research.
Nearly all universities used expulsion to deal with some cheats
Higher education institutions used 25 different penalties ranging from expulsion and fines to loss of marks, the study for watchdog the OIAHE found.
A graded approach reflecting differing types of plagiarism was needed, said the Independent Adjudicator for Higher Education Baroness Ruth Deech.
But students must be treated fairly and consistently, she added.
The report examined the spread and range of penalties available for plagiarism in 168 UK higher education institutions (HEIs) and found "substantial variations" throughout the sector.
It was commissioned after Baroness Deech, who heads the Office of the Independent Adjudicator in Higher Education which handles complaints against universities, expressed concerns about a lack of consistency.
However, she said it was not necessarily a problem that a wide range of penalty measures were used.
"The point is to have some consistency and equity in the way they're applied.
"Plagiarism could mean somebody using 12 words that aren't their own to a foreign student not understanding what they are doing to someone deliberately stealing thousands of words from someone else.
"But what students want and what is fair is some consistency."
She continued: "Plagiarism really must be rooted out - it's entirely unacceptable but the punishment must fit the crime."
Expulsion was the most frequently cited penalty and was used by 99% of HEIs surveyed.
Nearly two-thirds of HEIs (60.7%) used a formal warning at the "warning stage", the research suggests.
Just over a quarter (26%) docked marks proportional to the amount of plagiarised material used and 12.7% used fines ranging from £100 to £1,000.
Around a third of institutions had a range of graded penalties tailored to specific offences but with enough flexibility for the system to work well, the researchers said.
Some 18.5% used a strictly defined tariff system which, the researchers said, risked being too inflexible with specific penalties available for a specific types of offences.
But some 29.4% had a list of penalties they use for all types of plagiarism without specifying which types of offences warranted which penalties.
This system risked penalties being applied in an arbitrary and unfair way, researchers said.
"One student could be expelled and another could get no further action," said one of the report authors, Dr Fiona Duggan of the Plagiarism Advisory Service.
But she added that many of the institutions studied said they were revising their regulations, with many recognising the need for a fairer way of doing things.
"There's a recognition that there needs to be some regard to this and an awful lot are working towards this."
The team now intend to look at the way in which the regulations on dealing with plagiarism are put into practice.
The research was funded by the Joint Information Systems Committee Plagiarism Advisory Service.