Officers searched a person known to them as a previous knife offender in a taxi on April 10.
A stop and search was carried out, following which a knife was allegedly found in his waistband.
The knife recovered by police is a 30-inch machete in a red and black sheath and curved hand guard.
The police added that this was the sixth time the suspect had been arrested for alleged or actual knife offences in 12 months.
A Met spokesperson said: “On 10 April, eagle-eyed officers from Uniformed Proactive Team 2 spotted a known knife carrier in a taxi near Kidbrooke.
“He was stopped, searched—and found with a 30-inch machete in his waistband. That’s his 6th knife arrest in 12 months.”
