The AAP on Friday urged the central government to probe the source of the "mysterious" spike in bank deposits in the second fortnight of September.The Aam Aadmi Party said Rs 3 lakh crore worth of deposits before demonetisation confirms its stand that those close to Prime Minister Narendra Modi knew about the plan to spike Rs 500 and 1,000 notes.Addressing the media here, AAP leader Ashish Khetan quoted a Business Standard article which said around Rs 3 lakh crore was deposited in Fixed Deposits in the last 15 days of September.On November 12, Chief Minister Arvind Kejriwal quoted another media report to say around Rs 4 lakh crore was deposited in banks in the July-September period, Khetan said."Finance Minister Arun Jaitley said the spike in deposits was due to arrear payment of the Seventh Pay Commission," Khetan said. "But this money was not deposited in saving or salary or current accounts, but in FDs."Also, the total arrear payments amounted up to Rs 45,000 crore. How does that explain deposits worth Rs 3 lakh crore?"Khetan said around Rs 1.5 lakh crore was withdrawn from the FDs the very next month."The central government says if one deposits more than Rs 2.5 lakh in his account they will be issued income tax notice, they may even get raided. But the government doesn't want to probe this unexplained spike of Rs 3-4 lakh crore in cash deposits," the AAP leader said.The government on November 8 demonetised all Rs 500 and Rs 1,000 notes, saying this was done to fight the menace of fake currency as well as black money and corruption.