Image caption Methoxetamine is used by some as an alternative to Class C drug ketamine

The legal high methoxetamine, or mexxy, is to become the first drug to be banned temporarily under new government powers, the Home Office has said.

The drug, used as an alternative to ketamine, will be made illegal for up to 12 months.

The government's advisers will then decide whether it should be permanently controlled.

Early indications suggest it may have been used by four people in the time leading to them dying.

There have been no confirmed deaths relating to the drug and tests are continuing.

The substance was referred to the Advisory Council on the Misuse of Drugs (ACMD) earlier this month.

Its tests found evidence that use of methoxetamine can lead to "significant additional toxicity", including agitation, a faster heart rate and higher blood pressure, as well as unsteadiness on the feet.

These symptoms are rarely seen with ketamine or other recreational drugs, the advisers said.

'Ruins lives'

Anyone caught making, supplying or importing the drug will face up to 14 years in prison and an unlimited fine under the Misuse of Drugs Act 1971, the Home Office said.

Police and border officials will also be allowed to search or detain anyone they suspect of having the drug and seize, keep or dispose of a substance they suspect is methoxetamine.

Crime Prevention Minister Lord Henley said: "Making this drug illegal sends a clear message to users and those making and supplying it that we are stepping up our fight against substances which are dangerous and ruin the lives of victims and their families.

"It is important for users of these harmful substances to understand that just because they are described as legal highs, it does not mean they are safe or should be seen as a 'safer' alternative to illegal substances."

ACMD chairman Professor Les Iversen said: "The evidence shows that the use of methoxetamine can cause harm to users.

"Many of the health effects... are similar to those of ketamine, which is already controlled under the Misuse of Drugs Act.

"Users have also reported experiencing other serious effects including agitation, cardiovascular conditions and hypertension."