A total of 16 cases of the strain – known as B.1.621 – have been discovered so far and experts from Public Health England are urgently testing.
Most of the cases have been linked to overseas travel and there is currently no evidence of community transmission in the UK, PHE said.
They also added that there is no evidence to suggest that the strain makes vaccines less effective.
READ MORE: TUI cancels more vacations in latest update, including Bulgaria and Italy
Public Health England said in a statement: “Sixteen confirmed cases of B.1.621 have been identified across the country to date, and the majority have been linked to overseas travel.
“There is currently no evidence of community transmission in the UK.
“There is currently no evidence that this variant causes more severe disease or makes currently deployed vaccines less effective.
“PHE is performing laboratory tests to better understand the impact of mutations on the behavior of the virus. “
PHE also released data today showing that cases of the Delta variant have increased by 33,716 since last week to a total of 286,765.
The new figures suggest that the Delta variant may be 46% more likely to cause reinfection than the Alpha variant first identified in Kent.
PHE data shows that while the overall chances of re-infection are very low, the Delta variant, first identified in India and which accounts for around 99% of cases in the UK, is at higher risk.
It came as new figures showed the distribution of the number of people hospitalized with the Delta variant who received one or both doses of a Covid-19 vaccine.
From June 21 to July 19, some 1,788 people were admitted to hospital after testing positive for Delta.
Of these, 970 (54%) had not been vaccinated, while 530 (30%) had received both doses.
A total of 3,692 people have so far been hospitalized with the Delta variant, of which 2,152 (58%) were unvaccinated and 843 (23%) were fully vaccinated.
From February to mid-July, among those under 50 who had received the two vaccines, only four patients died with the Delta variant out of 15,346 cases in this group (0.02%).
There were 34 deaths among the unvaccinated in the same age group, among 119,063 Delta cases (0.02%).
Meanwhile, among those over 50 who received both vaccines, there were 220 deaths in 13,427 cases (1.64%).
And there were 131 deaths among the unvaccinated over 50s among 2,337 cases (5.6%).
For the latest Manchester Evening News email updates, click here.