Then hire an escrow agent so the suspicion from the investors will be removed.
You can hire any person on the list
Recommended bitcointalk escrow services as you can see on the table, there are some who are into alts but the rest are obvious for bitcoin only transactions.
Gotta post the same link but living free do posted it already which is the most accurate answer when you search up for trusted escrows into this forum which you wouldnt really worry based into their reputation and credibility.
People would really remove out suspicions if they do find out that their investments are being held with a reputable escrow by this forum. Feels like op is confident enough to reach out targets.