A couple including a British man has been arrested by UK authorities as part on an ongoing investigation into a massive cyber attack that disabled 123 of 187 police security cameras in Washington DC just prior to the inauguration of Donald Trump on 20 January.

It has emerged that less than 24 hours before the president was sworn into office, officers from the National Crime Agency (NCA) arrested a British man and a Swedish woman – both 50-years-old – after receiving a request from US authorities.

The pair were detained at an address in Streatham, south London, and have been bailed until April 2017.

According to The Sun, the arrests were linked to the US cyber attack, however UK authorities have refused to elaborate further on the suspected links.

Additionally, the NCA, which is the UK's equivalent to the FBI, has not yet commented on what intelligence was provided that led to their discovery.

An NCA spokesman told IBTimes UK: "We can confirm that officers executed a search warrant at an address in Natal Road, SW16 on the evening of 19 January. Enquiries are ongoing and we are unable to provide further information at this time."

On 27 January, it emerged that hackers had infected up to 70% of the storage devices recording data from police CCTV cameras with ransomware, causing major concerns as security preparations were being made for the inauguration.

The computer malware, which typically locks down systems until the victim pays a fee to the cybercriminals, left a slew of cameras unable to record between 12 January and 15 January. One secret service official, Brian Ebert, maintained safety was "never jeopardised."

US authorities believe the cyber attack may have been a test run, with another computer assault potentially planned for the day of the ceremony. Details about the ongoing investigation remain scant, and the names of the detained suspects are yet to be released.

Initially, city officials, speaking to The Washington Post, said the hack and extortion attack appeared to be "localised", a claim that clashes with the news of arrests in the UK.

Archana Vemulapalli, the city's chief technology officer (CTO), said no ransom was paid to the hackers and the issue was resolved internally by reinstalling software and restarting each infected system individually. No other DC computer networks were impacted, she added.

British authorities are ramping up efforts to combat the rising threat of cyber crime with a recently-expanded five-year National Cybersecurity Strategy. Chancellor Philip Hammond has publicly warned about the dangers of "escalating cyber attacks" to UK citizens.