A prized Pablo Picasso portrait was attacked over the weekend at the Tate Modern in London.

According to the museum, Bust of a Woman (1944) was defaced by a visitor Saturday, December 28. The painting, which is valued at £20 million ($26 million), according to the BBC, was immediately taken off view. Initial reports said that it had suffered a rip.

“An incident occurred at Tate Modern on 28 December when a member of the public attempted to damage a painting,” the Tate said in a statement to the press following the attack. “The person was swiftly apprehended and has been charged. Police are investigating. The work of art is with our conservation team for expert assessment. Tate Modern remains open.”

The alleged attacker was Shakeel Ryan Massey, a 20-year-old northwest London resident who was apprehended shortly the supposed attack took place. Charged with criminal damage, Massey appeared before a court on Monday where he indicated that he would fight the charge. 

The suspect, denied bail, will remain in custody until his pre-trial hearing, set for January 30. 

Pablo Picasso in Mougins, France in October 1971. Photo: Ralph Gatti/AFP/Getty Images.

A representative from the museum declined to share more information on the incident, citing the fact that the event is still under investigation by London police. 

Painted in Paris in the spring of 1944, during the final months of Nazi occupation, Bust of a Woman depicts Picasso’s famed muse—and fellow artist—Dora Maar. It belongs to a private collection and has been on long-term loan to the museum since 2011.

The last time such a high-profile vandalization took place at the Tate was in 2012, when Polish artist Vladimir Umanets defaced a 1958 Mark Rothko painting, Black on Maroon. Umanets, who claimed the act was an “artistic statement” on behalf of his own self-created Yellowism movement, was sentenced to two years in prison.