The Kenya Revenue Authority (KRA) is now seeking bank transactions of Mombasa Governor Ali Hassan Joho.
KRA has written to the Diamond Trust Bank (DTB) asking the bank to furnish them with Joho's statement from 2011 to date.
The letter dated 14th March 2017 is written by Justus Kiuvu on behalf of Commissioner Investigations.
On Sunday Joho described the action as part of blackmail by Jubilee coming less than a week after President Uhuru Kenyatta vowed to teach the outspoken governor a lesson.
"Now KRA have written to DTB asking for my statement and I want to tell President Uhuru Kenyatta that I have three accounts; DTB, Barclays and Stanbic. If they want all the money they can take it but I can never relent," Joho said in Lamu Sunday.
The governor has had run-ins with the Jubilee regime for the last three years.
The government has been clamping down on his family business which include Container Freight Stations (CFSs).
Last week security forces kept Joho and his supporters from Uhuru's function at the Mtongwe Ferry Channel.
Mombasa County traffic marshals were ordered off the streets as armed police took over.
At the function to launch a ferry at Mtongwe, Uhuru accused Joho of trailing him like "his wife" and "chest thumping to appear a hero by attacking the President." "They should stop following me. I am not his wife. He should come here and explain what he has done for this country," an agitated Uhuru told residents of Mtongwe, adding that "he (Joho) should not play with us or we will teach him a lesson."