SAN DIEGO.- A heavy helmet and a woman's chest that didn't look right led U.S. Customs officers to seize six pounds of methamphetamine worth an estimated $121,000 in two incidents, authorities announced.

The first incident occurred at 9:15 a.m. Sunday when a 23-year-old man tried to enter the United States through the Otay Mesa crossing on a Yamaha 2007 motorcycle.

A Customs and Border Protection officer referred the man, a U.S. citizen, to secondary inspection. There, an officer noticed that the man's helmet was unusually heavy. An X-ray inspection revealed an anomaly in the helmet.

Agents found a plastic bag hidden in the lining that contained about 4.5 pounds of methamphetamine, which had an estimated street value of $92,000.

The second incident occurred around 5 p.m., also on Sunday, when a Mexican woman, 22, tried to enter the United States through the pedestrian crossing at San Ysidro.

"The CBP officer noticed discrepancies under the woman's clothing near her chest, and referred her for a more intensive inspection," according to the release issued Monday.

Officers found six plastic packages hidden in the woman's brassiere, containing almost a pound and a half of methamphetamine, which had an estimated street value of about $29,000, the release said.

In both incidents, which CBP said were unrelated, the suspects were placed in federal custody.