Homeland Security Secretary Kristi Noem’s purse containing US$3,000 in cash was stolen while she was dining at a popular Washington DC restaurant over the weekend, an incident now under investigation by the US Secret Service.

Noem was eating with her family at The Capital Burger when she felt what she thought was her grandchild brush against her leg, said a person familiar with the incident. Moments later, she realised her purse was missing, according to the person, who is not authorised to speak publicly.

Inside the Gucci shoulder bag were Noem’s DHS security badge, credit and bank cards, passport, blank cheques, prescription medication, driving licence and a Louis Vuitton Clemence wallet, the person said. Her government-issued phone was recovered and has been accounted for.

Surveillance footage showed a white male suspect enter the restaurant at 7.52pm on Sunday, wearing dark trousers, a fur-collared jacket, trainers and a white N95 mask. He sat at a table next to Noem’s at 7.55pm, angled his chair towards her and appeared to watch the floor, according to a law enforcement document reviewed by Bloomberg.

As Noem looked away, the suspect used his foot to slide her purse under his table, then picked it up, covered it with his jacket, and left at 7.56pm. Noem discovered the bag was missing when she stood up to leave.

Noem visits a prison in El Salvador on March 26. Photo: AFP

Noem has served as one of the Trump administration’s most visible figures on immigration enforcement, frequently appearing in television ads and social media campaigns ordering migrants to go home or be found and deported. She has posed on horseback at the southern border region, accompanied federal agents on raids and championed tough-on-immigration messaging in media appearances.