In the biggest seizure of narcotics being smuggled from Pakistan in recent years, the Customs seized over 500 kg heroin, valued at around Rs 2,700 crore, concealed in a consignment of salt, officials said on Sunday.The seizure of 532 kg heroin at the Integrated Check Post at the Attari border, some 30 km from here, was an all-time high, Commissioner, Customs, Dipak Kumar Gupta told reporters.He said this was one of the biggest-ever seizures of heroin by any Indian agency on the India-Pakistan border and "the biggest achievement in the annals of the Indian Customs history".The heroin, concealed in 15 gunny bags of a rock salt consignment that was coming from Pakistan, was detected on Saturday, he said.Gupta said one sack in the consignment was found to have white coloured granular substance. On examination of the 600 bags, 15 bags were suspected to have narcotic material and on their examination, all were found to contain heroin, having net weight of 532 kg, and mixed narcotics of 52 kg.The value of the seized heroin in the international market is approximately Rs 2,700 crore.Two people -- mastermind Tariq Ahmed Lone belonging to Jammu and Kashmir's Handwara and an importer from Amritsar -- were arrested.Smuggling of drugs along Punjab's 553-km long border with Pakistan is common.