According to ITV reporter Jonathan Swain, the man was able to climb the gates and bypass heat sensors, CCTV and armed guards to gain access to the grounds of the palace. It took the police four minutes to stop the man, Swain said.
Buckingham Palace told ET that they have no comment regarding the incident.
The breach came nearly 37 years after Buckingham Palace's most well-known security incident, when 30-year-old Michael Fagan gained access to the queen's bedroom while she was there. The 1982 incident lasted about 10 minutes, Swain said.
"This intruder got into the palace almost 37 years to the day since Michael Fagan ended up getting inside the queen’s bedroom," a royal source told The Sun. "There is a genuine theory and very real fear that he could have been launching a copycat operation."