Thai customs displayed over three tonnes of confiscated African ivory worth $6m (£3.96m) on 27 April, the second largest seizure in Thailand's history.

Five-hundred-and-eleven pieces of African elephant tusks originating from Kenya's Mombasa were seized on 25 April by Thai authorities.

The 3.1 tonnes shipment, disguised in bags of tea leaves, had boarded a cargo ship in Kenya in March and passed through several ports from Sri Lanka, Malaysia, Singapore to Thailand. Authorities said that better intelligence had led to the seizure on Saturday.

"Officials knew the ports where they (the smugglers) usually send out the tusks from Africa. We know the country and the ports, so if they use Thailand as a country to pass through, we will monitor more carefully," said General Dapong Ratanasuwan, the Minister of Natural Resources and Environment.

"The National Police, one of the departments responsible for solving this problem, has arrested the investors or people involved in the confiscation," he added.

Officials said the final destination listed in official documents was Laos. Last week, Thai authorities confiscated four tonnes of ivory, the largest bust of its kind in Thai history. The confiscation led to the arrest of suspects.

The seizures come as Thailand - a top destination for African ivory smuggling in Asia - is under increasing pressure to regulate its illegal ivory trade.

Thailand was given until the end of March to take measures to shut down domestic trade in illegal elephant ivory or face sanctions under the Convention on the International Trade of Endangered Species (Cites).

Any sanctions could impact Thailand's trade in species covered by the convention, including ornamental plants, such as orchids.