A door that was taken from London’s Grenfell Tower and tested could only resist fire for half as long as it was intended to, police said this week.

London’s Metropolitan Police experts tested a Grenfell Tower apartment front door, designed to resist fire for 30 minutes, and found that it only resisted fire for about 15 minutes, police said in a statement.

The test was part of what the police described as a “comprehensive investigation” into what happened when a huge fire engulfed the 24-story Grenfell Tower on June 14, 2017.

A fire is seen at Grenfell Tower in west London, June 14, 2017.(Natalie Oxford/PA Wire via AP, FILE) A fire is seen at Grenfell Tower in west London, June 14, 2017.

The Metropolitan Police said the forensic examination phase is ongoing and they are not able to comment on what impact the test result could have on the criminal investigation.

A huge fire engulfs the 24 story Grenfell Tower in Latimer Road, West London in the early hours of this morning in this June 14, 2017 file photo in London.(Gurbuz Binici /Getty Images, FILE) A huge fire engulfs the 24 story Grenfell Tower in Latimer Road, West London in the early hours of this morning in this June 14, 2017 file photo in London.

The fire killed 70 people, according to the Metropolitan Police. A stillborn baby was also recorded as a victim.

The Metropolitan Police has previously said that exterior cladding, fitted to the building, failed all safety tests.