A total of 24 people are now being held in custody in Britain.
Scotland Yard alleges suspected Islamic militants planned to use liquid explosives to bomb up to 10 US bound aircraft.
Police said the new suspect was arrested in the Thames Valley area in southeastern Britain, where several houses were raided last week.
The suspect was arrested under the Terrorism Act 2000 and is in custody at a police station in the Thames Valley area, police said.
The 23 people who had been arrested earlier are all British-born Muslims, mainly of Pakistani descent.
No details were immediately available on the latest person arrested.
Police had been scouring woodland around the town of High Wycombe, north-west of London.
According to British media, one of the houses raided in High Wycombe, may have been used to mix the chemicals.
Britain seeks suspect’s extradition
Britain is reportedly seeking the extradition of Rashid Rauf, a British al-Qaeda suspect held in Pakistan.
Pakistan has described him as a "key player" in the conspiracy.
The Times has reported British High Commission officials in the Pakistani capital, Islamabad, had begun the extradition process.
London's Metropolitan police and the British Home Office have declined to confirm or deny the reports.
Britain does not have an extradition treaty with Pakistan, but a Home Office spokeswoman said extradition was still possible.
It’s understood a number of international treaties signed by Britain and Pakistan, or a one-off request would enable his transfer.
A Pakistani Foreign Ministry spokeswoman, Tasnim Aslam, said the possibility remained open because Rauf was a British citizen.
The 25 year old British national who is alleged to have links to al-Qaeda was arrested in a raid in Pakistan’s east on August 3.
Pakistan has alleged Rauf gave details of the conspiracy which was crucial in thwarting the plot.
Security officials said another Briton and five Pakistanis had been arrested with Rauf.
Rauf’s brother, Tayib, is allegedly shown in closed circuit TV footage in Britain.
The footage is said to have been taken just hours before his arrest and it shows the 22 year old wearing a white T-shirt and beige trousers.
Passenger profiling
The security measures implemented in the wake of the arrests continues to create controversy.
There has been heated debate over whether personal details such as religion and travel history should be used to pinpoint terror suspects.
The idea of passenger profiling has been rejected by Muslim leaders who warn it could alienate the nation's 1.5 million Muslims.
The Times newspaper reported that the Department for Transport is considering a profiling system to select people behaving suspiciously.
Under the proposal, they may also be targeted if they have an unusual travel pattern or a certain ethnic or religious background.
It said the government was considering introducing a screening system that allows security staff to focus on those passengers who pose the greatest risk.
John Stevens, former head of London's Metropolitan Police, told the News of The World that airport chaos could be reduced by targeting passengers for more rigorous checks, with "young Muslim men" a focus.
Muslim leaders warned that profiling would backfire.
"If the community is profiled as a community, there will be a backlash and no-one is going to co-operate with the police and the authorities, which is important to fight terror," Abdul Bari, secretary general of the Muslim Council of Britain, said.
New security measures
Britain has eased a ban on airline cabin baggage as it scaled down the threat level to "severe" from the highest level "critical".
But passengers continued to suffer major delays and airlines were still forced to cancel some of their flights.
Mountains of baggage piled up at Heathrow, the world's busiest international airport, left over from last week's chaotic departures.
British Airways said it was still trying to clear a backlog of 5,000 bags and deliver them to their owners.
"We've got articulated lorries going into cities in the UK and Europe and we are using Fed Ex to send bags to Europe and the US," a spokeswoman for the airline said.
"We currently have around 5,000 bags waiting to be despatched to
their owners."
The airline has been forced to cancel 1,100 flights as a result of the heightened security checks and has said it may seek compensation from airport operator BAA.
12yo beats British security
British police want to determine how a 12-year-old boarded an aircraft at London's Gatwick airport without a passport or a boarding pass.
The boy boarded an airliner bound for Portugal on Monday when British airports were still operating at their highest level of security.
The boy had run away from a care home in Merseyside in western England and travelled to London by train.
He also managed to get through airport security, board a plane and take a seat before the Monarch Airlines crew noticed he had no documents.