In a scene echoing a horror movie, Gavin Hyatt, of Witney, in Oxfordshire, England, staggered into his general physician’s office bleeding from his belly button.

The 30-year-old man reeled in agony as his stomach ruptured — and the remains of his embryonic twin spilled out.

“It was like something from (the movie) 'Alien',” said his stunned physician, Dr. Joe Santos. “I didn’t believe Gavin when he said something was coming out of his belly button until I saw him.”

Doctors said the growth, also known as a parasitic twin, was Hyatt’s identical brother who died in their’s mother’s womb early in the pregnancy.

The 4-centimeter fetus became embedded in Gavin’s tissue and stayed in his stomach for the next 30 years.

Hyatt said doctors were often stumped by the lump in his stomach.

“Some thought it was a cyst, others an in-grown hair,” he said.

Hyatt said he keeps the twin in a jar at home and calls it “Little Gav.”

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