Kenyan authorities seized 228 whole elephant tusks and 74 others in pieces as they were being packed for export in the port city of Mombasa, police and wildlife officials said.
Poaching has surged in the last few years across sub-Saharan Africa, where gangs kill elephants and rhinos to feed Asian demand for ivory and horns for use in traditional medicines.
Wildlife authority Kenya Wildlife Service (KWS) officers and police confiscated the ivory in a raid at a warehouse in the port city of Mombasa, KWS said in a statement.
Police arrested one suspect and were searching for another who escaped, noting that the suspect in custody tried to bribe police officers by offering them 5 million shillings ($57,100).
Arthur Tuda, KWS officer in charge of the coastal region, said some of the ivory could have come from as far away as the Democratic Republic of Congo.
Kenya has imposed stiffer penalties - longer jail terms and bigger fines - for wildlife poaching or trafficking, saying poaching is harming tourism, a major earner of foreign exchange.
KWS said in March that Kenya poachers have killed 18 rhinos and 51 elephants this year. In 2013, 59 rhinos and 302 elephants were killed, compared with 30 rhinos and 384 elephants in 2012.
Kenyan officers seized 13.5 tonnes of ivory in Mombasa last year, mostly originating in other countries in the region. At least 249 suspects have so far been arrested this year and prosecuted for various wildlife offences, KWS said.
In January, a Kenyan court convicted a Chinese man of smuggling ivory and ordered him to pay a fine of 20 million shillings ($233,000) or serve seven years in jail, the first sentencing since Kenya introduced the new anti-poaching law.
($1 = 87.5000 Kenyan shillings)