The embattled chairman of the board that oversees the city’s troubled rail project abruptly resigned Friday under calls for state and federal investigations on whether his company benefited from the sale of rail-­related city general obligation bonds and whether he should have disclosed potential conflicts of interest.

The Honolulu Authority for Rapid Transportation announced Friday that HART board Chairman Tobias Martyn resigned from the volunteer board “for personal reasons.”

State Sen. Kurt Fevella (R, Ewa Beach-Iroquois Point) — the state Senate’s minority leader — has written to the FBI, Federal Transit Administration and state Attorney General’s Office requesting that they investigate HART on a variety of concerns based on media reports.

They include “possible criminal acts” committed by Martyn related to “Rail General Obligation Bond Issuances,” regarding Martyn’s “affirmative vote requesting the Honolulu City Council approve the issuance and sale of ($292 million in) rail general obligation bonds. This action was taken while Mr. Martyn also served as Stifel Financial Corp’s Branch Manager and Vice President of Investments.”

The city has not responded to requests for information about Stifel’s role in the sale of the bonds.

Fevella told the Honolulu Star-Advertiser late Friday that he has not heard from the FBI, FTA or state attorney general on his requests, but has been told by the Office of Information Practices that it plans its own investigation.

OPI could not be reached for comment late Friday.

“I’m glad he (Martyn) made the right decision, and I just pray that the HART board doesn’t consider (former HART Chairwoman, Congresswoman and incoming board member Colleen) Hanabusa for the position,” Fevella told the Star-Advertiser. “Hanabusa left HART in dismay the last time. She’s part of the bloc. All of them should not be there. … If they really care about the project, they’ll step down. Toby did the right thing.”

Martyn was appointed to the HART board on Nov. 18, 2018, and became chairman in September. His term was scheduled to expire in January 2023.

Since he was appointed by the HART board, Fevella had called on Martyn’s board colleagues to remove him.

City Councilwoman Heidi Tsuneyoshi, a sometime HART critic, told the Star-Advertiser that Martyn’s resignation “was the appropriate action to take at this time” but should not affect any investigations into whether he behaved appropriately.

Tsuneyoshi said she “still wants answers and more clarity as to the issues that were presented regarding his involvement in the floating of bonds. I look forward to continued questioning. I still want answers. Although I believe it’s appropriate for him to take this step, I don’t think it negates our need for transparency regarding bond issuances and the hiring of Hanabusa.”

Hanabusa was the only person to bid on a HART consulting contract written for her that was worth nearly $1 million. Following uproar over her contract to lobby county, state and federal officials on behalf of HART, Hanabusa declined the contract, and it was no longer offered.

She was then appointed to the HART board by Mayor Rick Blangiardi and is scheduled to take her seat when the board meets this month.

Some HART board members told the Star-Advertiser on Friday that Martyn’s resignation offers the board an opportunity to bring in a new member with needed expertise who will conduct appropriate oversight of the rail project, which faces a $3 billion budget shortfall, is projected to cost $12.449 billion and is not expected to be completed until March 2031.

“I think we’re going to need somebody with contracting experience and some kind of construction experience,” HART board member Natalie Iwasa told the Star-Advertiser. “Definitely, I don’t think it does anybody any good to have a ‘yes man’ type of person. That’s what gets us into trouble, when we have somebody who’s just going to go along without really looking into the details.”

At the same time, Iwasa acknowledged that “anybody who would be really good would be hesitant because it’s really hard to know that you’re going to be in the public eye and criticized. … It takes somebody who has the ability to put in a lot of time and wants to see a good outcome and has a thick skin, basically.”

HART board member Joe Uno, whose own reappointment to the HART board by the City Council remains in limbo, said Martyn’s vacancy “opens up things.”

Uno said he hopes that whoever the HART board selects to replace Martyn “is not going to be a Hanabusa clone.”

“I feel this is a real great opportunity for the board to take a new direction,” Uno said.

Uno and Iwasa spoke as individual members of the HART board and not on behalf of HART or the board.

Hanabausa has not responded to previous requests for comments on her HART contract or appointment to the HART board by Blangiardi.